1. Technical Field
Synthetic structures for the repair of soft tissue are described. Such structures may include, in embodiments, fibrillar structures that may be utilized to approximate the physical characteristics of soft tissue and thus may be useful as implants to promote the repair of soft tissue.
2. Background
There are currently several ways in which various types of soft tissues such as ligaments or tendons, for example, are reinforced and/or reconstructed, such as, bioprosthetic techniques or synthetic techniques. Bioprosthetic techniques include, for example: autografting, where tissue from the patient's body is used; allografting, where donor tissue from the same species is utilized; and, xenografting, in which tissue from a donor of a different species is used. Other bioprosthetic techniques for soft tissue attachment, reinforcement, and/or reconstruction have included small intestinal submucosa (SIS) or other naturally occurring extracellular matrix (ECM), and a naturally occurring ECM or ECM component. Bioprosthetic techniques may be used alone or in conjunction with synthetic devices for tissue repair.
Synthetic techniques of tissue reconstruction, reinforcement and repair do not utilize donor material. Mechanical techniques such as suturing the torn or ruptured ends of the tissue are used to restore function. Sutures may be reinforced through other synthetic non-bioabsorbable or bioabsorbable materials.
One example of a material often used in conjunction with sutures in tissue repair is a surgical mesh. Surgical meshes may be used to support and/or reinforce damaged or weakened portions of the body. Surgical meshes may also be used as a scaffold for tissue regeneration. In this regard, the mesh must be sufficiently porous to allow for growth of tissue through the mesh after implantation. The healing tissue grows through porous openings in the implanted mesh, thereby assimilating the mesh and adding structural integrity to the tissue. Surgical meshes may also be utilized in tendon repair. Tendons of the body are under continuous movement causing stress and tension or pulling in the tendon. Accordingly, surgical meshes used in tendon repair should exhibit sufficient yield and tensile strength to endure the weight and stress or strain put on the tendon. However, the mesh should also be flexible and pliable enough to move with the tendon without breaking. The mesh should also be suturable and have a high suture pullout strength to allow the implant to function properly in vivo.
Various surgical meshes attempt to provide strength by knitting, weaving, braiding, or otherwise forming a plurality of yarns into a support trellis. These meshes may be produced with monofilament or multifilament yarns made of materials such as polypropylene and polyester. Surgical mesh formed of monofilament yarn provides satisfactory reinforcement ability, but is often stiff and has limited pliability.